90158-84-2

Upstream product

• 31508-44-8 2-phenylpropionic acid methyl ester 
• 84892-13-7 methyl 2-bromo-2-phenylpropanoate 
• 492-37-5 hydratropic acid 

Relevant academic research and scientific papers

Thermal cleavage of the 3,4 bond in a cyclobutane-1,2-dione

Pyrolysis of trans-3,4-dimethyl-3,4-diphenylcyclobutane-1,2-dione results in an isomerization interpreted to involve formation of a dioxatetramethyleneethane biradical. This biradical would arise from a hitherto unprecedented 3,4 bond cleavage.

The synthesis and stereospecific solid-state photodecarbonylation of hexasubstituted meso- and d,l-ketones

Tertiary carbanions were trapped with half an equivalent of diphosgene to give meso- and d,l-hexasubstituted ketones in moderate yields and modest diastereoselectivities. The ketones were also synthesized by a step-wise synthesis in which the carbonyl group was first installed as an acid before activation and the second nucleophilic attack. This second method gave lower yields but similar diastereoselectivites. Steric limits of both methods were also determined. The photolysis of the resulting crystalline ketones gave a mixture of products in solution, but took place chemoselectively and diastereospecifically in the solid-state. The Royal Society of Chemistry and Owner Societies.

Dependence of the reactivities of titanium enolates on how they are generated: Diastereoselective coupling of phenylacetic acid esters using titanium tetrachloride

Oxidative coupling of phenylacetic acid esters was easily achieved by treating the esters with TiCl4 and then adding Et3N to the resulting solution. The products consisted of dl- and meso-2,3-diphenylsuccinic acid esters with the Claisen condensation product, and the ratio of these products depended on the reaction conditions. Reaction conditions suitable for high dl selectivity were determined, and a dimer of titanium enolate was postulated as an intermediate responsible for the high dl selectivity. The selectivities were compared with those in known oxidative couplings in which titanium enolate intermediates are prepared through lithium enolates and silyl enol ethers. The results suggest that the reactivities of titanium enolates intermediates depend on how they are generated.

Homolytic Reactions of Ligated Boranes. Part 16. Enantioselective Hydrogen-atom Abstraction by Chiral Amine-Boryl Radicals: Catalytic Kinetic Resolution of Esters and of Camphor

UV irradiation of an oxirane solution containing di-tert-butyl peroxide, an amine-alkylborane complex (in which the B-alkyl group is optically active) and a racemic ester or camphor as substrate, gives rise initially to the tert-butoxyl radical which rapidly abstracts hydrogen from the complex to form an optically active amine-boryl radical.The amine-boryl radical then abstracts hydrogen enantioselectively from a C-H group α to the carbonyl group in the substrate to regenerate the amine-alkylborane.This abstraction reaction has been used to bring about catalytic kinetic resolution of the substrate, using the bis(isopinocampheylborane) complex of N,N,N',N'-tetramethylethylenediamine and some of its derivatives as catalysts.After partial consumption of the substrate, the amount remaining and its enantiomeric excess (ee) have been used to derive enantioselectivity constants for hydrogen-atom abstraction.Enantioselectivity varies considerably with the structure of the substrate.The highest selectivity was observed for hydrogen abstraction from dimethyl 2,2-dimethyl-1,3-dioxolane-trans-4,5-dicarboxylate, when after 75percent consumption of initially-racemic ester at -90 deg C, the residual substrate showed an ee of 97percent.A transition-state model is proposed to account for the observed enantioselectivities.

Electroreduction of Methyl 2-Bromo-2-phenylpropanoate on a Vitreous Carbon Electrode: meso- and DL-Dimethyl 2,3-Dimethyl-2,3-diphenylsuccinate

The electrochemical reduction of ethyl α-bromophenylacetate (1) and methyl 2-bromo-2-phenylpropanoate (5) in dry dimethylformamide on a vitreous carbon electrode has been studied.Dimeric products are formed as a consequence of controlled potential electrolysis of (1) and (5) on a reticulated vitreous carbon electrode.By this route, meso- and DL-diethyl 2,3-diphenylsuccinate and -dimethyl 2,3-dimethyl-2,3-diphenylsuccinate are obtained from ester (1) and (5), respectively.A triester is also obtained among the products.The spectral data (n.m.r., mass spectra) show the structure of this triester to be almost certainly MeO2CCMePhC6H4CMeCO2MeCMePhCO2Me (9).To explain the results, a mechanism is proposed, involving the formation of dimer (10) as an intermediate.